Forgotten legacy of Dr Livingstone

Circa 1850: Dr Livingstone is attacked by a lion during an expedition to Africa. Picture: Getty

From http://www.scotsman.com
HE’S lauded as the great ­explorer who opened up ­Africa while working tirelessly as a Christian missionary.

But now Dr David Livingstone’s almost forgotten legacy as a pioneering medical scientist is to be re-examined in the run-up to the 200th anniversary of his birth in March.

Leading scientists and campaigners from around the world will gather at Glasgow University next month to recognise the work in the field of tropical medicine that Livingstone carried out on his 19th-century journeys across the continent.

Among his medical discoveries and achievements in primitive conditions was to make the use of quinine – a tree bark extract – the standard treatment for malaria, the development of arsenic compounds to treat sleeping sickness and the linking of disease transmission to insect bites.

Michael Barrett, professor of biochemical parasitology at Glasgow University, who will be leading the conference, said Livingstone’s work was groundbreaking. “As a medical missionary, with his astonishing powers of observation and ability to survive in Africa where others had not been able to, it’s pretty reasonable to say that he was a pioneer in making these observations.”

He said the Scots explorer’s crowning achievement, though, had been to set the treatment of malaria with ­quinine on a firm scientific footing.

“He didn’t discover that quinine was active against malaria,” he said. “During medieval times it was clear that this substance was effective against fevers, which is now known to be malaria. But because Livingstone was an avid reader, he’d noted that quinine had successfully been used against African fevers in the past.

“Though nobody at that time knew that it was caused by parasites, he’d observed that you were more likely to get these fevers where there were mosquitoes present.

“So whenever he travelled in Africa he carried huge amounts of quinine, and this is essentially the reason Livingstone was able to travel so far into Africa. Prior to that, almost every Africa explorer who had tried to do this had died because of malaria.”

Livingstone also observed that the overuse of quinine would result in a ringing in his ears, which allowed him to gauge the maximum dose he could manage.

Blantyre-born Livingstone, who died aged 60 in what is now modern-day Zambia, studied Latin and medicine in Glasgow.

He spent 30 years in Africa, and by the time of his death in 1873 it is estimated he had travelled more than 30,000 miles into uncharted territories, mostly on foot.

Experiencing terrible conditions and disease throughout his time there, Livingstone eventually succumbed to a combination of malaria and internal bleeding.

But Barrett said the Scot’s meticulous recording of his observations was to prove a vital source of information for scientists that followed.

Livingstone recorded such conditions as elephantiasis, a marked swelling caused by parasitic worms, as well as identifying the threat posed by the tsetse fly, which spreads the potentially lethal disease sleeping sickness.

He then pioneered the use of arsenic compounds in treating sleeping sickness, recording how he had dosed a horse that had fallen sick after being bitten by tsetse flies with arsenic oxide. The explorer noted that while the horse showed a temporary recovery, the side-effects of arsenic were severe.

However, decades later, scientists who had developed a deeper understanding of the disease referred back to Livingstone’s notes from his expeditions, made the link between his observations and the disease, and started to work on creating less toxic arsenic compounds which, even to this day, are used to treat the condition,

Addressing the symposium will be international experts from the World Health Organisation, the Bill & Melinda Gates Foundation, St George’s University of London and the University of Glasgow, which has more professors of parasitology than anywhere else in the world.

Barrett explained: “What we’re trying to do is string together a series of talks that show how a number of diseases that Livingstone saw and observed are still with us today, and we’ll link them together by reminding people what his observations about those diseases were.”

Nat Edwards, project leader of the David Livingstone 200 organisation, which is orchestrating events to mark the anniversary, said Livingstone’s work in medicine encapsulated the explorer’s talent.

“I think the medical stuff gets to the heart of it,” he said. “When he was ten, he went to work – he came from a very working class background with nine people living in a single room – and of course he gave the larger part of his earnings to his mother.

“But with what he had left he used that money to buy Ruddiman’s Rudiments Of The Latin Tongue, a Latin textbook, because at the age of ten he had set his heart on a medical education.”

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Discoveries: Livingstone’s contributions to tropical medicine

Establishing the use of quinine as an effective treatment for malaria. Until then, investigating the interior of Africa had been almost impossible because of the threat of the debilitating potentially lethal disease.

Observing the conditions in which malaria was likely to occur. Though he did not make the connection between mosquitoes and the spread of the disease, he did make the observation that their presence did denote the likelihood of malaria: “Myriads of mosquitoes showed, as probably they do, the presence of malaria.” This was 30 years before the link was formally proved.

Observing that the tsetse fly was a scourge to animals. Although Livingstone did not make the link between the insect and human diseases, he realised that the fly would have to be eradicated if modern agricultural methods were to be introduced.

Being the first to use arsenic to treat what would be later identified as sleeping sickness. Though he used the substance on a horse, his notes on the incident helped scientists to develop less toxic treatments for humans.His experiences in Africa led him to make connections between the environment and climate and diseases such as pneumonia, typhoid and dysentery.